Previous studies have shown considerable variability in the spatial footprint of mass bleaching events on the GBR, with the southern region remaining relatively unimpacted by thermal stress in the past 4 mass bleaching events.
The sf output can be used to generate interactive maps
to explore the extent of DHW across reefs in the current 2024 event
(click individual reefs to see the reef_name / label_ID and DHW from
previous events in 1998, 2002, 2012, 2016, 2017, & 2020):
library(tidyverse)
library(janitor)
library(sf)
library(stars)
library(raster)
library(tmap)
library(ggplot2)
library(terra)
library(tidyterra)
gbr_shape_dhw <- readRDS("/Users/rof011/GBR-coral-bleaching/data/gbr_shape_dhw.RDS")
gbr_shape_dhw2 <- gbr_shape_dhw |>
st_simplify(preserveTopology = FALSE, dTolerance = 10)
gbr_shape_dhw_map <- gbr_shape_dhw2 %>%
mutate(across(where(is.numeric), round, digits = 1))
tmap_mode("view")
tm_basemap("Esri.WorldImagery") +
tm_shape(gbr_shape_dhw_map) +
tm_polygons(col="dhw_max_2024", title="DHW Max 2024", palette="-RdBu",
breaks= seq(0,20,1), alpha=0.8, legend.show=TRUE,
popup.vars = c("dhw_max_1998", "dhw_max_2002", "dhw_max_2016",
"dhw_max_2017", "dhw_max_2020", "dhw_max_2022", "dhw_max_2024")) +
tm_view(set.view = c(145.3, -14.5, 10))